Though Northstrider is notoriously insular, preferring to keep to himself and not carving out his own territory, he is considered the Monarch of unbound sacred artists and there have been several instances when he has taken other artists under his aegis. So far we've seen two instances of this happening, the creation of his facility Ghostwater, and his upcoming team for the Uncrowned tournament.
The Ghostwater facility is one of the most advanced places our protagonists have visited in all of Cradle so far. While the Night Wheel Valley was no doubt a powerful space for cultivation, it is essentially a farm. By comparison, while it was running, the Ghostwater facility was a cutting edge research station where Northstrider commissioned his followers to push the boundaries of Cradle technology and even after being looted by Heralds it was still home to countless treasures. This is where we see that even though Northstrider does not generally maintain a following, when he chooses too he can bring incredible resources to bear. However, Northstrider does abandon the facility when it becomes apparent that it will not create a Presence.
We have yet to see Northstrider's team for the Uncrowned tournament, but simply given his participation we know that he has to collect 12 Underlords to fight in his name since each faction is providing 4 teams of 3. We see Northstrider approaching the Beast King looking for recruits at the end of Underlord suggesting that he has a good working relationship with him and they may in fact count as allied.